I have a weird issue on a 97 lhs w/3.5l. Car is hard to start hot, fine when cold. Physically it cranks like an old chevy that had the timing too far advanced and I hear pre-ignition. Sometimes it starts and sometimes it cranks once and can't get past it. Funny part is I disconnected the wire connector to the coil pack and tried it and it does the same thing and tries to start but sounds like it's firing on one cylinder. How could it try to fire without power to the coil pack? Excessive carbon build up on 1 piston causing pre ignition?? I thought maby a leaky injector but I didn't see any leaking in the intake?? I did a cyl leak down test all good, 90% or better. Anybody ever see this before ??